Propeller



April 1966 A. E. JOCZ 3,246,699

PROPELLER Filed June 10, 1964 INVENTOR. r--

United States Patent 3,246,699 PROPELLER Armin E. .Ioez, Waukegan, 111., assiguor to Outboard Marine Corporation, Waulregan, 111., a corporation of Delaware Filed June 10, 1964, Ser. No. 373,926 2 Claims. (Cl. 170173) The invention relates to propellers and to methods of manufacturing propellers.

The invention provides a propeller including a series of drop-forged blades, each of which includes a tang at the base thereof, and a die cast hub into which the tangs are embedded.

In accordance with the invention, one process for manufacturing the above-described propeller includes the steps of drop-forging a series of blades, each blade including at the base thereof a tang, placing the blades in proper relation to each other in a die casting machine, and die casting a hub about said tangs to thereby complete formation of the propeller.

In the preferred practice, each tang is provided with one or more lengthwise channel-shaped recesses to insure retention of the blades in the die cast hub. Thus, in the disclosed construction, the tangs generally have a cross section of I beam-like channeled configuration. The outer lip or flange of the tang at the rear face of the blade is of greater dimension than the corresponding lip or flange at the forward face of the tang to increase resistance to the bending moment set up during propeller operation. Radial grooves extending transversely of the tang are also provided to further insure rigid retention of the blades within the hub.

Manufacture of propellers as above outlined offers various advantages including increased blade strength afforded by the drop forge operation and minimization of machining with respect to the hub, because of the dimensional accuracy afforded by use of the die casting operation. In addition, the disclosed process is highly economical and lends itself to mass production techniques.

Other objects and advantages will become known by reference to the following disclosure and accompanying drawings, in which:

FIGURE 1 is a fragmentary elevational view, partly broken away and in section, of a propeller manufactured in accordance with the invention.

FIGURE 2 is a fragmentary sectional view taken along lines 22 of FIGURE 1.

FIGURE 3 is a fragmentary view of a typical section through a blade.

FIGURE 4 is a fragmentary perspective view, partly illustrating the tang formed at the base of the blade.

The propeller 11 shown in FIGURE 1 includes a hub 13 and a series of propeller blades 15, three in the disclosed construction. The hub is adapted to be nonrotatably mounted on a propeller shaft (not shown) and, in the disclosed construction, extends generally cylindrically about an axis 16. As will be explained further, the hub 13 is diecast of any suitable diecasting metal so as to embed the blades 15 therein to provide an integrated propeller structure.

Each propeller blade 15 is generally of identical construction and includes a blade part 17 having any desired configuration best suited for intended use, together with a tang part 19 extending from the base of the blade part 17.

In order to solidly anchor the blades 15 to the hub 13, the tang parts 19 are each formed to provide an end portion 21 and a connecting portion 23 which extends between the end portion and the blade part 17 and which provides a neck having at least one dimension which is less than a corresponding dimension in the end portion.

"ice

In the specifically disclosed construction, the tang parts 19 extend for the length of the base of the blade part and are each formed so as to have a cross section, when seen in a plane containing the axis 16 of said hub 13, as shown best in FIGURES 2 and 3, of generally I beam configuration, including an inner flange which has been previously identified as the end portion 21, and an outer flange 27. The flanges 21 and 27 are connected by a generally radially extending web, which has previously been identified as the portion 23. Defined between the flanges 21 and 27 to each side of the web or portion 23 are channel-shaped grooves or recesses 29 which extend, in part, in the direction of the hub axis 16, and which, in the completed construction, are filled with die cast metal to interlock the blades to the hub. The rearwardly extending part 30 of the outer flange 27, located adjacent to the blade part base, is of heavier construction, i.e., of larger dimensions as compared to the forwardly extending part of the outer flange 27 to resist the bending moment imposed during propeller operation. In order to prevent shifting of the blade 15 relative to the hub 13 arcuately about the hub axis 16, each tang part 19 is also provided with one or more transverse recesses 31 which are shown best in FIGURE 4 and which extend generally in the direction of the hub axis 16.

In acordance with the invention, the blades 15 are separately fabricated by drop forging in order to obtain advantageous directional physical properties imparted thereby. However, at least some of the advantages of the invention can be obtained without utilizing drop forged blades.

When a sufficient supply of the blades 15 is on hand, the desired number of blades are placed in proper relation to each other in any suitable diecasting machine. The details of the diecasting machine are not important to the present invention. The hub 13 is then diecast about the tang parts 19 to provide an integrated propeller structure.

Flow of the diecast material into the recesses 31 and into the grooves 29 between the flanges 21 and 27 serves to solidly anchor the blades 15 in the hub 13 against both radial and arcuate displacement. As the diecasting operation also affords a high degree of dimensional accuracy, only minimum amounts of machining are necessary to complete the manufacture of a finished, integrated propeller. Moreover, both the drop forging and diecasting operations readily lend themselves to economical mass production methods.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. A propeller comprising a generally cylindrical hub having a central axis, a series of blades each including a blade part extending from said hub, and a tang part extending in said hub, said tang parts each having a cross section of generally I beam shape in a plane containing the axis of said hub and having at least one groove extending in the direction of said hub axis.

2. A propeller comprising a generally cylindrical hub having a central axis, a series of blades each including a blade part extending from said hub, and a tang part extending in said hub, said tang parts each having a cross section of generally I beam shape in a plane containing the axis of said hub, said sections including spaced inner and outer flanges each including forwardly and rearwardly extending parts, and a web connecting said spaced flanges, said rearwardly extending part of said outer flange being larger than the forwardly extending part of said outer flange.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Coppus 29-156.8 Calkins.

Fitzpatrick.

McMahan 29156.8

Webb 29156.8

Carlson 170173 4 FOREIGN PATENTS 364,002 12/1931 Great Britain.

MARK NEWMAN, Primary Examiner.

JULIUS E. WEST, Examiner.

W. E. BURNS, Assistant Examiner. 

1. A PROPELLER COMPRISING A GENERALLY CYLINDRICAL HUB HAVING A CENTRAL AXIS, A SERIES OF BLADES EACH INCLUDING A BLADE PART EXTENDING FROM SAID HUB, AND A TANG PART EXTENDING IN SAID HUB, SAID TANG PARTS EACH HAVING A CROSS SECTION OF GENERALLY I BEAM SHAPE IN A PLANE CONTAINING THE AXIS OF SAID HUB AND HAVING AT LEAST ONE GROOVE EXTENDING IN THE DIRECTION OF SAID HUB AXIS. 